Re: games and antivirus
depends on your AV program I think. If you're using something that uses little resources like avast, AVG, avira, NOD32 etc. then it won't hurt. but if you're using a program that eats memory like mcafee, then it's a good idea to turn it off IMO. I don't turn mine off and I see no performance difference from when it's on or off but then again I'm using AVG and that uses maybe 2MB max.
Desktop: Dell Dimension E510, 2.5GB RAM, Intel P4 3.0GHZ, 250GB HDD, Windows Vista Premium. Might not be the best, but the old girl is still running good.